The subject matter disclosed herein relates to the art of turbomachines and, more particularly, to a nozzle for a turbomachine.
In general, gas turbine engines combust a fuel/air mixture that releases heat energy to form a high temperature gas stream. The high temperature gas stream is channeled to a turbine via a hot gas path. The turbine converts thermal energy from the high temperature gas stream to mechanical energy that rotates a turbine shaft. The turbine may be used in a variety of applications, such as for providing power to a pump or an electrical generator.
In a gas turbine, engine efficiency increases as combustion gas stream temperatures increase. Unfortunately, higher gas stream temperatures produce higher levels of nitrogen oxide (NOx), an emission that is subject to both federal and state regulation. Therefore, there exists a careful balancing act between operating gas turbines in an efficient range, while also ensuring that the output of NOx remains below mandated levels. Current integrated gasification combined cycle, multi-nozzle quiet combustor (IGCC MNQC) nozzles always burn fuel in a diffusion mode and dry low NOx (DLN1) primary nozzles sometimes burn in a diffusion mode. In the case of IGCC turbomachines a significant amount of diluent is required to maintain NOx at acceptable levels.